This invention relates to an apparatus for dispensing soft serve food products such as ice creams, yogurts, sherbets, and other frozen dessert confections.
Soft serve frozen confections are widely used in the food industry and have a broad customer appeal. Although ice creams are the most widely known product dispensed in a soft serve form, an expanding market based on alternative frozen confections such as yogurts also exists. A soft serve confection is dispensed by extrusion into an edible cone or other suitable container, and is generally intended for immediate consumption.
A soft serve confection can be easily extruded from the dispensing apparatus in a variety of patterns or shapes. A common manner of dispensing a frozen confection consists of extruding a continuous ribbon or rod that can be coiled on itself to form a cone having a beehive shape. Soft serve confections ideally will have sufficient strength to retain the extrudate shape for a period of time, even when subjected to changes in orientation such as would occur during consumption.
The dispensing temperature of the soft serve frozen confection typically ranges from about 16.degree. F. to 21.degree. F. This temperature range is critical, with lower temperatures being characterized by difficulties in extrusion of the soft serve frozen confection, mechanical hardness, and inferior taste quality due to the adverse reaction of taste buds to a low temperature frozen confection, often resulting in a "burning" sensation. Temperatures higher than the normal soft serve confection-dispensing range result in a low viscosity product with undesirable rheological characteristics that do not permit retention of the extrudate shape and are unsuitable for later processing such as dipping in chocolate or crushed nutmeats.
Because of the critical narrow temperature range for soft serve frozen confections it is not feasible to transport the frozen confections at their normal dispensing temperature.
To overcome this problem, the food service industry presently utilizes on-site production of the soft serve frozen confections. The soft serve confection can be shipped from the manufacturer to the food product retailer as a powder, a refrigerated liquid, or in a frozen state. If the confection is not in a liquid state, it is converted to the liquid state at the site of the food product retailer. For example, a confection shipped in the frozen state is allowed to completely thaw to liquid form, or water is added to the powdered form. This liquid is converted on-site to a soft serve frozen confection by an agitated freezing process in a soft serve frozen confection dispenser.
Although on-site production of the soft serve frozen confection permits the successful manufacture and service of soft serve frozen confections, the method does present some problems of its own. The machinery necessary for on-site production is complicated and expensive. Scraper blades that agitate the frozen confection during its on-site formation require sharpening or replacement, and inadvertent freeze-up of the machinery is a continual worry. The cost in electricity for operating the freezing unit is substantial, and special heavy duty electric wiring may be necessary to handle the power requirements of the freezer. Because of the agitation process, addition of extra elements, such as nutmeats, candies or fruits, to the soft serve confection is normally impossible. Frequent regular cleaning of the parts of the frozen confection dispenser is also necessary to prevent blockage and reduce the chance of bacterial contamination.
A further disadvantage of the on-site production is the increased risk of bacterial contamination presented at each stage of the process. Although the liquid is refrigerated, the chance of bacterial contamination is greatly increased over the frozen form. This danger is increased by the possibility of improper cleaning of the machinery, which could result in a seed culture of bacteria capable of contaminating newly added liquid confection. Additionally, quality control of on-site producers of soft serve confections can be inferior as compared to a central manufacturer, resulting in uneven product appearance, taste, and form.
It is accordingly an object of the present invention to provide a soft serve frozen confection dispenser capable of extruding a soft serve frozen confection and suited for use in a commercial setting.
Another object of the invention is to provide a device for dispensing soft serve confections that is sanitary, mechanically simple, easy to clean, draws small amounts of electric power, and in specific embodiments is capable of portable use.
It is a further object of the present invention to provide a device that is capable of serving a soft serve frozen confection without the formation of undesirable ice crystals in the frozen confection.
Yet another object of the present invention is to provide a device that is capable of dispensing soft serve frozen confections which include extra flavoring ingredients such as fruit or candy pieces.
The present invention accordingly comprises a soft serve frozen confection dispenser that is capable of dispensing certain products such as yogurt in a soft serve form free of the undesirable characteristics formerly associated with such soft serve yogurt products.
Apparatus for use in dispensing frozen confection is provided according to the present invention. In one embodiment, such apparatus includes a bag assembly designed to store a predetermined quantity of frozen confection to be dispensed. The bag assembly includes a collapsible container and a sleeve around the container. The sleeve provides a girdle or corset means for the collapsible container.
The collapsible container is formed to include an interior chamber configured to hold either liquid or frozen confection therein. Prior to filling, the collapsible container is disposed in a longitudinally extending channel formed in the sleeve. The collapsible container expands radially about its longitudinal axis as it is filled with a partly frozen confection until it reaches a maximum girth controlled by the surrounding sleeve. The sleeve is undersized in diameter with respect to the container to cause the maximum girth of the filled collapsible container to be less than the girth the container would otherwise have if the container were not placed in the sleeve as the container was being filled with partly frozen confection. Essentially, the sleeve behaves like a girdle with respect to the container to limit expansion and minimize stretching of the collapsible container as it is filled. Once filled, the bag assembly and its contents are further frozen to a sub-zero (.degree.F.) temperature at the dairy so that it can be transported to a remote freezer unit located at the site at which the frozen confection is to be dispensed from the collapsible container.
In other preferred embodiments, the collapsible container includes a discharge tube connected to the container at an outlet aperture and configured to extrude frozen confection. The collapsible container is stored in a freezer unit cooled by a refrigeration system. An outlet conduit is provided to connect the discharge tube to a dispensing spigot mounted on the freezer unit. Means is provided for applying enough pressure to the container to cause it to collapse and discharge frozen confection to the dispensing spigot via the discharge tube and outlet conduit. Extrusion of frozen confection at the dispensing spigot is controlled by a manually operated valve assembly.
Advantageously, the apparatus further includes cooling means surrounding the outlet conduit for cooling the outlet conduit to a subfreezing temperature using cooled air provided inside the freezer unit by the refrigeration system. Desirably, the cooling means includes a sleeve made of a thermally conductive material and the outlet conduit extends through a longitudinally extending passageway formed in the sleeve.
The sleeve has a first end section disposed in the freezer unit to expose the sleeve to the subfreezing temperature in the freezer unit and a second end section contacting the outlet conduit to enhance heat transfer between the sleeve and each of the outlet conduit and dispensing spigot. Advantageously, the outlet conduit and dispensing spigot is cooled by the sleeve to minimize melting of frozen confection in those regions of the apparatus caused by exposure to warm air circulating around the dispensing spigot outside of the freezer unit. Of course, any melting of frozen confection anywhere in the apparatus could lead to crystallization problems in the confection if the melted confection is later refrozen.
In another embodiment, the discharge tube includes a first flange connected to the collapsible container at its outlet aperture and a second flange disposed in a passageway formed in the outlet conduit. The effective area of the first flange exposed to frozen confection in the container is larger than the effective area of the second flange exposed to frozen confection in the passageway. The uniform pressure generated in the collapsible container as it is compressed by a piston means to discharge frozen confection through the discharge tube acts to apply a greater load to the first flange than is applied to the relatively smaller second flange. Accordingly, the discharge tube is moved by such a greater load in the outlet conduit passageway in a direction toward the dispensing spigot to retain the discharge tube in the passageway during compression of the collapsible container. Advantageously, this feature helps to prevent inadvertent withdrawal of the discharge tube of the collapsible container from the outlet conduit of the dispensing spigot.
The piston means used to compress the collapsible container to extrude frozen confection through the discharge tube is driven by compressed air produced by an air compressor. Desirably, the air compressor itself is situated in a cold region of the freezer unit itself so that only dehydrated refrigerated air will be drawn into the air compressor to be compressed and then provided to operate the piston means. This source of dehydrated refrigerated compressed air will help to reduce icing problems normally experienced by pistons moving in cold environments using warm compressed air. Icing can impair piston movement.
A storage locker is also provided in a location inside the freezer unit to store unused bags of frozen confection for long periods of time. Each storage locker has a separate door which is normally kept closed to protect the frozen confection stored in the locker from exposure to any warm air introduced into the freezer unit upon opening of the main access door into the freezer unit. Advantageously, the buffer against warm air provided by the storage locker reduces the likelihood that any of the frozen confection stored therein will experience melting and recrystallizing problems while in long-term storage inside the freezer unit.
The freezer unit is set up to maintain soft serve frozen confection substantially within the normal soft serve dispensing temperature range of 17.degree. F. to 21.degree. F. Ideally, the freezer unit will be sufficiently large to contain replacement collapsible containers filled with soft serve frozen confections as well as maintain the soft serve frozen confection in the dispensing section of the apparatus within the normal soft serve dispensing temperature range.
The soft serve frozen confection held by the collapsible container in the dispensing section has an ideal dispensing temperature. The dispensing section includes thermal insulation means for maintaining the soft serve frozen confection at a constant ideal dispensing temperature. The maintenance of a constant temperature without flucuation within the dispensing section inhibits ice crystal formation in the soft serve frozen confection that can result from temperature changes such as are encountered in the cyclic temperature fluctuations that normally result from the duty cycle of a freezing unit. The thermal insulation means can be a layer of foam or other passive thermal insulation which completely or partially surrounds the collapsible containers.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.